• Journal of Platform Technology
• /
• v.6 no.4
• /
• pp.78-86
• /
• 2018

In this paper, a VR-based cyber hiking system was designed to provide virtual reality for famous mountains that can offer the real senses and feelings of hiking in supporting environmental factors of actual mountains such as the temperature, air, sound, echoes, etc., of the mountain the user wants to climb. The VR-based cyber hiking system that reflects real-time site conditions is largely consisted of the data collection module that collects data from the live site, multiple drive modules that enables the user to feel real senses using data from the sites, and sensor module to detect the stimuli provided by the drive modules and the user's physical body transition. Unlike existing VR-based hiking systems, the proposed cyber hiking system not only provides simple virtual reality for the wanted mountain, but can also provide the natural conditions of real mountains and implement the uphill and downhill of hiking routes. In particular, it has the effect of providing fun and game elements to users by excluding unnecessary conditions and risks that may arise in actual hiking and instead supporting augmented realities such as squirrels on actual hiking paths. In addition, in providing users with the changes in their body before and after hiking, it is expected to be effective in providing diverse feedback such as the height, gradient, and speed of mountain hiking.

• Composites Research
• /
• v.31 no.6
• /
• pp.371-378
• /
• 2018

In this study, the thermoelastic properties of poly lactic acid (PLA) based nanocomposites are predicted by molecular dynamics (MD) simulation and a micromechanics model. The stereocomplex mixed with L-lactic acid (PLLA) and D-lactic acid (PDLA) is modeled as matrix phase and a single walled carbon nanotube is embedded as reinforcement. The glass transition temperature, elastic moduli and thermal expansion coefficients of pure matrix and nanocomposites unit cells are predicted though ensemble simulations according to the hydrolysis. In micromechanics model, the double inclusion (D-I) model with a perfect interface condition is adopted to predict the properties of nanocomposites at the same composition. It is found that the stereocomplex nanocomposites show prominent improvement in thermal stability and interfacial adsorption regardless of the hydrolysis. Moreover, it is confirmed from the comparison of MD simulation results with those from the D-I model that the interface between CNT and the stereocomplex matrix is slightly weak in nature.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.29 no.1
• /
• pp.38-49
• /
• 2011

This study is foundation study to understand the Location and the composition of Joseon Royal Tombs, the purpose is to bring light on the types of Sinro Eoro in Joseon Royal Tombs. The type was grouped into Regular type and Irregular type by relations with the approach way, Hongsalmun and Jeongjagak, and the Irregular type was grouped into Curved type and Divided type. The making pattern of Sinro Eoro was divided into three period, the former period, the transition period and the latter period, by the length and the Irregular type. The Regular type was affected by the length of Geonwonreung's Sinro Eoro as the minimum standard in the former period. The result of examining the Irregular type's present condition in Jeongreung, Hyeonreung, Mokreung, Jangreung and Yeongreung, narrow topograph and the waterway were important factors to decide the type. In other words, the type of Irregular Sinro Eoro was constructed by a topography and a waterway in the length of Geonwonreung's Sinro Eoro as the minimum standard.

• Korean Journal of Metals and Materials
• /
• v.47 no.9
• /
• pp.523-532
• /
• 2009

In this study, four API X80 linepipe steel specimens were fabricated with varying cooling rates and finish cooling temperatures, and their microstructures and crystallographic orientations were analyzed to investigate the effects of cooling conditions on their tensile and Charpy impact properties. All the specimens consisted of acicular ferrite, granular bainite, and secondary phases such as martensite and martensiteaustenite constituent. The volume fraction of secondary phases increased with increasing cooling rate, and the higher finish cooling temperature resulted in the reduction in volume fraction and grain size of secondary phases. According to the crystallographic orientation analysis data, the effective grain size and unit crack path decreased as fine acicular ferrites having a large amount of high-angle grain boundaries were homogeneously formed, thereby leading to the improvement of Charpy impact properties. The specimen fabricated with the higher cooling rate and lower finish cooling temperature had the highest upper shelf energy and the lowest energy transition temperature because it contained a large amount of fine secondary phases homogeneously distributed inside fine acicular ferrites, while its tensile properties well maintained.

• Journal of Korean Academy of Nursing
• /
• v.51 no.3
• /
• pp.320-333
• /
• 2021

Purpose: The study was conducted to explore the experiences of job retention among working people with mental illness. Methods: The participants were members with mental illness at the S Community Mental Health Center in Gyeonggi Province and who had been working for more than six months. The data were collected through in-depth interviews with 11 participants between June 27 and August 20, 2018. The data were analyzed through Corbin and Strauss's grounded theory method. Results: The core category was struggling to take root in the community as a productive member. The core phenomenon was the desire to be a productive person, and the causal condition was the willingness to change for a purposeful life. The action and interaction strategies included maintaining regular living patterns, maintaining medication, developing one's tips for self-management, and self-approval. The intervening conditions were difficulties in forming social relationships, presence of symptoms, social resources, and acceptance of one's mental illness. The consequences were restoration of family relationships, healthy pleasure through work, social inclusion, development of self-worth, and transition to an independent person. Conclusion: Working people with mental illness are struggling to take root in the community as a productive member. This study suggests that a holistic understanding of the job retention experience among people with mental illness is required. The findings will provide the basis for developing interventions that can improve job retention among working people with mental illness.

• Research in Community and Public Health Nursing
• /
• v.33 no.3
• /
• pp.269-278
• /
• 2022

Purpose: This study analyzed the retention factors of Korean community health practitioners who sustained over 20 years based on a multi-dimensional framework. This study suggests global implications for nurses working in rural or remote areas, even during a worldwide pandemic. Methods: The participants were 16 Korean community health practitioners who worked in rural or remote locations for over 20 years. This study identified nurses' key retention factors contributing to long service in rural and remote areas. This is a qualitative study based on the narrative method and analysis was conducted using grounded theory. A semi-structured questionnaire was conducted based on the following: the life flow of the participants' first experience, episodes during the work experience, and reflections on the past 20 years. Results: First, personal 'financial needs' and 'callings' were motivation-related causal conditions. The adaptation of environment-work-community was the contextual condition leading to intervening conditions, building coping strategies by encountering a lifetime crisis. The consequences of 'transition' and 'maturation' naturally occurred with chronological changes. The unique factors were related to the 'external changes' in the Korean primary health system, which improved the participants' social status and welfare. Conclusion: Considering multi-dimensional retention factors was critical, including chronological (i.e., historical changes) and external factors (i.e., healthcare systems), to be supportive synchronously for rural nurses. Without this, the individuals working in the rural areas could be victimized by insecurity and self-commitment. Furthermore, considering the global pandemic, the retention of nurses is crucial to prevent the severity of isolation in rural and remote areas.

• Journal of Advanced Navigation Technology
• /
• v.27 no.4
• /
• pp.410-416
• /
• 2023

Unlike geostationary satellite communication systems, low-earth orbit(LEO) satellite communication systems move at relatively high speeds, and the angle with the ground device is not fixed and varies over a wide range. The propagation channel condition between satellites and ground nodes cannot be assumed line of sight(LOS) anymore. This paper analyzes the low-orbit multi-path fading satellite channel model that can occur in LEO satellite communication systems and Doppler frequency transition caused by high-speed maneuvering of LEO satellites and presents effective equalization techniques for OFDM and SC-FDE transmission methods suitable for multi-path frequency selective fading satellite channel models. In addition, this paper compares and analyzes the performance of OFDM and SC-FDE transmission methods in multipath fading LEO satellite channel environment using the proposed equalization techniques through simulations. Simulation results showed that SC-FDE outpeformed OFDM.

• Journal of Ginseng Research
• /
• v.47 no.3
• /
• pp.440-447
• /
• 2023

Background: The human hair follicle undergoes cyclic phases-anagen, catagen, and telogen-throughout its lifetime. This cyclic transition has been studied as a target for treating hair loss. Recently, correlation between the inhibition of autophagy and acceleration of the catagen phase in human hair follicles was investigated. However, the role of autophagy in human dermal papilla cells (hDPCs), which is involved in the development and growth of hair follicles, is not known. We hypothesized that acceleration of hair catagen phase upon inhibition of autophagy is due to the downregulation of Wnt/β-catenin signaling in hDPCs, and that components of Panax ginseng extract can increase the autophagic flux in hDPCs. Methods: We generated an autophagy-inhibited condition using 3-methyladenine (3-MA), a specific autophagy inhibitor, and investigated the regulation of Wnt/β-catenin signaling using the luciferase reporter assay, qRT-PCR, and western blot analysis. In addition, cells were cotreated with ginsenoside Re and 3-MA and their roles in inhibiting autophagosome formation were investigated. Results: We found that the unstimulated anagen phase dermal papilla region expressed the autophagy marker, LC3. Transcription of Wnt-related genes and nuclear translocation of β-catenin were reduced after treatment of hDPCs with 3-MA. In addition, treatment with the combination of ginsenoside Re and 3-MA changed the Wnt activity and hair cycle by restoring autophagy. Conclusions: Our results suggest that autophagy inhibition in hDPCs accelerates the catagen phase by downregulating Wnt/β-catenin signaling. Furthermore, ginsenoside Re, which increased autophagy in hDPCs, could be useful for reducing hair loss caused by abnormal inhibition of autophagy.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.2
• /
• pp.133-142
• /
• 2023

The large process plant is currently implementing predictive maintenance technology to transition from the traditional Time-Based Maintenance (TBM) approach to the Condition-Based Maintenance (CBM) approach in order to improve equipment maintenance and productivity. The traditional techniques for predictive maintenance involved managing upper/lower thresholds (Set-Point) of equipment signals or identifying anomalies through control charts. Recently, with the development of techniques for big analysis, machine learning-based AAKR (Auto-Associative Kernel Regression) and deep learning-based VAE (Variation Auto-Encoder) techniques are being actively applied for predictive maintenance. However, this predictive maintenance techniques is only effective during steady-state operation of plant equipment, and it is difficult to apply them during start-up and shutdown periods when rises or falls. In addition, unlike processes such as nuclear and thermal power plants, which operate for hundreds of days after a single start-up, because the pumped power plant involves repeated start-ups and shutdowns 4-5 times a day, it is needed the prediction and alarm algorithm suitable for its characteristics. In this study, we aim to propose an approach to apply the optimal predictive alarm algorithm that is suitable for the characteristics of Pumped Storage Power Plant(PSPP) facilities to the system by analyzing the predictive maintenance techniques used in existing nuclear and coal power plants.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.289-289
• /
• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.